Lightweight distal plasma device

Abstract

The utility model discloses light-weight far-end plasma equipment, which is characterized in that a plasma chamber and an electronic switching type impedance matcher are arranged in a shell, and the electronic switching type impedance matcher is coupled to the plasma chamber and is used for being connected with an external radio-frequency power supply so as to output a radio-frequency power supply of the radio-frequency power supply to the plasma chamber. The electronic switching type impedance matcher comprises an impedance matching circuit, the impedance matching circuit at least comprises an inductor and two groups of electronic switching type capacitor units, and each electronic switching type capacitor unit comprises a plurality of change-over switches and a plurality of fixed capacitors. Therefore, a vacuum variable capacitor which is large in size and heavy is not used any more, and the size and the weight of the far-end plasma equipment are effectively reduced.

Description

Technical Field

[0001] The utility model relates to a plasma device, in particular to a plasma generator arranged outside a semiconductor process device. Background Art

[0002] See also Figure 4 As shown, a remote plasma device 60 is disposed on the top surface of a semiconductor process equipment 50, and when the process step of the process chamber is started, cleaning plasma is generated outside the semiconductor process equipment 50 and enters the process chamber to clean the inner wall of the chamber after the process.

[0003] The above-mentioned remote plasma equipment 60 mainly includes a plasma chamber 61, an impedance matcher 62 and a radio frequency power supply 63. When the remote plasma equipment 60 is started, the radio frequency power supply 63 also provides a radio frequency power supply to the plasma chamber 61 through the impedance matcher 62 to dissociate the externally injected gas to generate plasma, and then inject the plasma into the process chamber.

[0004] In order to facilitate independent control of the remote plasma device 60, the remote plasma device 60 currently sets the upper plasma chamber 61, the impedance matcher 62 and the RF power supply 63 in a device housing, so as to be conveniently installed on the top surface of the semiconductor process equipment 50. However, after actual operation, it is found that the impedance matcher 62 has a high maintenance frequency, so that subsequent maintenance personnel must disassemble the entire device from the semiconductor process equipment 50 to repair the impedance matcher 62 therein.

[0005] Please refer to Figure 5 As shown, the impedance matcher 62 includes a control circuit board 621, an inductor 624 and more than two vacuum variable capacitors 623; wherein the two vacuum variable capacitors 623 are electrically connected to two motors 622 respectively, and the control circuit board 621 drives the motors 622 to rotate the corresponding vacuum variable capacitors 623 to adjust the capacitance value of the vacuum variable capacitors 623. Therefore, the control circuit board 621 can adjust the capacitance value of the vacuum variable capacitors 623 by driving the motors 622 according to the current impedance of the plasma chamber 61, thereby changing the impedance of the impedance matcher 62. Since the impedance value of the vacuum variable capacitors 623 can be fine-tuned by rotating the motors 622, it can accurately match the current impedance of the plasma chamber 61, so as to achieve the best plasma generation efficiency.

[0006] In order to ensure the plasma cleaning efficiency of the remote plasma device, its impedance matcher uses more than two vacuum variable capacitors as capacitors of its matching circuit; however, the vacuum variable capacitor is large and heavy, and is arranged in the device housing together with the plasma chamber and the RF power supply, which does make the remote plasma device arranged on the top surface of the semiconductor process chamber unfavorable for subsequent maintenance and should be further improved. Utility Model Content

[0007] In view of the above-mentioned shortcomings of the current remote plasma device, the main purpose of the present invention is to provide a lightweight remote plasma device, which can effectively reduce the weight of the remote plasma device.

[0008] The main technical means used to achieve the above purpose is to make the lightweight remote plasma device include:

[0009] A housing comprising a gas inlet and a plasma outlet; wherein the plasma outlet is capable of communicating with an opening on a top surface of a semiconductor processing device;

[0010] a plasma chamber disposed in the housing and connected to the gas inlet and the plasma outlet, so that ionization gas can be injected into the plasma chamber from the gas inlet of the housing; and

[0011] An electronically switched impedance matcher is disposed in the housing and coupled to the plasma chamber, and is electrically connected to an external radio frequency power supply to output radio frequency power from the radio frequency power supply to the plasma chamber; wherein the electronically switched impedance matcher comprises:

[0012] A radio frequency input terminal, capable of being connected to an external radio frequency power supply;

[0013] a first RF output terminal connected to the plasma chamber;

[0014] an impedance detector electrically connected to the RF input terminal;

[0015] An impedance matching circuit, comprising at least one inductor and two sets of electronically switchable capacitor units, each of which comprises a plurality of switches and a plurality of fixed capacitors, wherein the fixed capacitors are respectively connected in series with the corresponding switches and then in parallel; and

[0016] A controller is electrically connected to the impedance detector to detect the impedance value of the plasma chamber and output the detected impedance value to the controller. The controller controls a plurality of switches of each of the electronically switched capacitor units of the impedance matching circuit according to the impedance value.

[0017] The capacitance values ​​of the fixed capacitors are partially the same, partially different, or completely different.

[0018] The impedance matching circuit is an L-shaped matching circuit, the two ends of the inductor are respectively connected between the RF input end and the first RF output end, and the two electronic switchable capacitor units are respectively connected between the two ends of the inductor and the ground end.

[0019] When the impedance value output by the impedance detector is substantially close to (50-J0)Ω, the controller stops controlling the switch of each of the electronically switched capacitor units of the impedance matching circuit.

[0020] When the impedance value output by the impedance detector is substantially close to (50-J0)Ω, the controller stops controlling the switch of each of the electronically switched capacitor units of the impedance matching circuit.

[0021] The RF power supply is a variable frequency RF power supply and is electrically connected to the controller; after the controller determines that the currently detected impedance value reaches a preset impedance value, it outputs a holding signal to the RF power supply, so that the RF power supply adjusts its variable frequency until the controller determines that the currently detected impedance value is substantially close to (50-J0)Ω and no longer outputs the holding signal, and the RF power supply stops adjusting its variable frequency; the RF power supply of the RF power supply provides a RF power of 13.56MHz±5%.

[0022] The electronically switched impedance matcher further comprises: a second RF output terminal; and a RF switching switch, comprising a common terminal and two switching terminals, wherein the common terminal is connected to the RF input terminal, one of the two switching terminals is connected to the impedance matching circuit through the impedance detector, and the other switching terminal is connected to the second RF output terminal, and the RF switching switch is electrically connected to the controller, and the controller controls its switching to selectively provide the RF power provided by the RF power supply to the plasma chamber or the second RF output terminal.

[0023] The electronically switched impedance matcher further comprises: a second RF output terminal; and a RF switching switch, comprising a common terminal and two switching terminals, wherein the common terminal is connected to the RF input terminal, one of the two switching terminals is connected to the impedance matching circuit through the impedance detector, and the other switching terminal is connected to the second RF output terminal, and the RF switching switch is electrically connected to the controller, and the controller controls its switching to selectively provide the RF power provided by the RF power supply to the plasma chamber or the second RF output terminal.

[0024] The electronically switched impedance matcher further comprises: a second RF output terminal; and a RF switching switch, comprising a common terminal and two switching terminals, wherein the common terminal is connected to the RF input terminal, one of the two switching terminals is connected to the impedance matching circuit through the impedance detector, and the other switching terminal is connected to the second RF output terminal, and the RF switching switch is electrically connected to the controller, and the controller controls its switching to selectively provide the RF power provided by the RF power supply to the plasma chamber or the second RF output terminal.

[0025] The electronically switched impedance matcher further comprises: a second RF output terminal; and a RF switching switch, comprising a common terminal and two switching terminals, wherein the common terminal is connected to the RF input terminal, one of the two switching terminals is connected to the impedance matching circuit through the impedance detector, and the other switching terminal is connected to the second RF output terminal, and the RF switching switch is electrically connected to the controller, and the controller controls its switching to selectively provide the RF power provided by the RF power supply to the plasma chamber or the second RF output terminal.

[0026] From the above description, it can be seen that the RF power supply is no longer installed in the shell of the lightweight remote plasma device of the utility model, and an electronically switched impedance matcher is mainly used, eliminating the use of large and heavy vacuum variable capacitors, effectively reducing the size and weight of the remote plasma device, which is beneficial to the subsequent maintenance of the remote plasma device set on the top surface of the semiconductor process chamber.

[0027] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments, but is not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 : A schematic diagram of a lightweight remote plasma device of the present invention installed on the top surface of a semiconductor process chamber.

[0029] Figure 2 : A circuit diagram of a first embodiment of a lightweight remote plasma device of the utility model.

[0030] Figure 3 : A circuit diagram of a second embodiment of a lightweight remote plasma device of the utility model.

[0031] Figure 4 : A schematic diagram of a remote plasma device installed on the top surface of a semiconductor process chamber.

[0032] Figure 5 : A top plan view of an impedance matcher installed in a remote plasma device.

[0033] Wherein, the reference numerals are:

[0034] 1: Lightweight remote plasma device 10: Shell

[0035] 11: Gas inlet 12: Plasma outlet

[0036] 20: plasma chamber 30, 30a: electronically switched impedance matching device

[0037] 301: RF input terminal 302: first RF output terminal

[0038] 303: second RF output terminal 31: electronically switched capacitor unit

[0039] 311: Switch 32: Electronically switched capacitor unit

[0040] 321: switch 33: controller

[0041] 34: Impedance detector 35: RF switch

[0042] 40: RF power supply 50: Semiconductor process equipment

[0043] 60: Remote plasma equipment 61: Plasma chamber

[0044] 62: Impedance matching device 621: Control circuit board

[0045] 622: Motor 623: Vacuum variable capacitor

[0046] 624: Inductor DETAILED DESCRIPTION

[0047] The present invention is directed to improving a remote plasma device used in semiconductor process equipment, and the technical content is described in detail below with reference to a plurality of embodiments and drawings.

[0048] First see Figure 1 As shown, the lightweight remote plasma equipment 1 of the present invention is used to be disposed on the top surface of a semiconductor process equipment 50 , and includes a housing 10 , a plasma chamber 20 and an electronically switched impedance matcher 30 .

[0049] The housing 10 includes a gas inlet 11 and a plasma outlet 12 ; wherein the plasma outlet 12 is used to communicate with the top surface of the semiconductor process equipment 50 .

[0050] The plasma chamber 20 is disposed in the housing 10 and is connected to the gas inlet 11 and the plasma outlet 12, so that the ionization gas can be injected into the plasma chamber 20 from the gas inlet 11 of the housing 10. After the plasma chamber 20 generates plasma, the plasma can be discharged from the plasma outlet 12 into a process chamber of the semiconductor process equipment 50.

[0051] The electronically switched impedance matcher 30 is disposed in the housing 10 and coupled to the plasma chamber 20, and is electrically connected to an external RF power supply 40 to output the RF power output by the external RF power supply 40 to the plasma chamber 20. In one embodiment, the RF power supply 40 provides 13.56 MHz ± 5% RF power.

[0052] Please refer to Figure 2 As shown, the electronic switchable impedance matcher 30 comprises an RF input terminal 301, a first RF output terminal 302, a controller 33, an impedance detector 34 and an impedance matching circuit; the RF input terminal 301 is connected to the external RF power supply 40, and the first RF output terminal 302 is connected to the plasma chamber 20. The controller 33 is electrically connected to the RF input terminal 301 through the impedance detector 34 to detect the impedance value of the plasma chamber 20, and outputs the detected impedance value to the controller 33.

[0053] The impedance matching circuit at least includes an inductor L and two groups of electronically switchable capacitor units 31, 32. Each of the electronically switchable capacitor units 31, 32 includes a plurality of switching switches 311, 321 and a plurality of fixed capacitors C11~C1n, C21~C2m. The fixed capacitors C11~C1n, C21~C2m are respectively connected in series with the corresponding switching switches 311, 321 and then connected in parallel. The capacitance values ​​of the fixed capacitors C11~C1n, C21~C2m may be partially the same, partially different, or completely different. The switches 311 and 321 are electrically connected to the controller 33, and the controller 33 controls the opening and closing of each of the switches 311 and 321 to determine the parallel connection of part or all of the fixed capacitors C11-C1n and C21-C2m in each of the electronic switchable capacitor units 31 and 32, so as to adjust the capacitance value of the fixed capacitors C11-C1n and C21-C2m connected in parallel, that is, to change the impedance value of the impedance matching circuit. In this embodiment, the impedance matching circuit is an L-shaped matching circuit, that is, the inductor L is connected in series with one of the electronic switchable capacitor units 32 and then connected between the impedance detector 34 and the first RF output terminal 302, and the other electronic switchable capacitor unit 31 is connected between the RF input terminal 301 and the ground terminal GND.

[0054] When the RF power supply 40 provides RF power to the plasma chamber 20 through the impedance matching circuit, the controller 33 detects the impedance value of the plasma chamber through the impedance detector 34; at this time, the controller 33 adjusts the capacitance values ​​of the two electronic switchable capacitor units 31 and 32 according to the currently detected impedance value, that is, controls the opening and closing of the switching switches 311 and 321 of each of the electronic switchable capacitor units 31 and 32, and determines the parallel connection of the two electronic switchable capacitor units 31 and 32. Several or all of the capacitors C11-C1n, C21-C2m connected in parallel determine the two capacitance values ​​of the L-shaped matching circuit until the controller 33 detects through the impedance detector 34 that the impedance value of the plasma chamber 20 is substantially close to the output impedance value of the RF power supply 40 (such as (50-J0)Ω), that is, stops controlling the opening and closing of the switches 311, 321 of each of the electronically switched capacitor units 31, 32. At this time, the reflected power will also be close to 0, at least 0.1.

[0055] In addition, the controller 33 can be further electrically connected to the RF power supply 40, and the RF power supply 40 is a variable frequency RF power supply. When the controller 33 determines that the current reflection coefficient reaches a critical impedance value (not (50-J0)Ω), it outputs a hold signal to the RF power supply 40, and the RF power supply adjusts its variable frequency until the controller 33 determines that the currently detected impedance value is substantially close to (50-J0)Ω and no longer outputs the hold signal, and the RF power supply 40 stops adjusting its variable frequency.

[0056] Please see again Figure 3 , is another embodiment of the lightweight remote plasma device of the present invention, most of its structures are the same as the above-mentioned embodiments, but its electronically switched impedance matcher 30a further includes a radio frequency switch 35 and a second radio frequency output terminal 303.

[0057] The RF switch 35 includes a common terminal COM and two switch terminals SW1 and SW2. The common terminal COM is connected to the RF input terminal 301. One of the two switch terminals SW1 is connected to the impedance matching circuit through the impedance detector 34. The other switch terminal SW2 is connected to the second RF output terminal 303. The RF switch 35 is electrically connected to the controller 33. The controller 33 controls its switching to selectively provide the RF power provided by the RF power supply 40 to the plasma chamber 20 or the second RF output terminal 303 through the impedance matching circuit. Since the second RF output terminal 303 is connected to the semiconductor process equipment 50 for use, the lightweight remote plasma equipment of the utility model can share an RF power supply 40 of the semiconductor process equipment 50.

[0058] In summary, the lightweight remote plasma device of the present invention no longer has an RF power supply installed in the housing, and mainly uses an electronically switched impedance matcher, eliminating the need for a large and heavy vacuum variable capacitor, and can further use a variable frequency RF power supply to allow the electronically switched impedance matcher to switch to an impedance close to that of the plasma chamber, and then fine-tune the reflection coefficient by the variable frequency RF power supply to make it smaller, so that the RF power transmitted to the plasma chamber can be effectively converted, thereby improving the cleaning efficiency of the semiconductor process chamber. In addition, the lightweight remote plasma device of the present invention can selectively provide the RF power provided by the RF power supply to the semiconductor process chamber, so the lightweight remote plasma device of the present invention can use the RF power supply electrically connected to the semiconductor process device.

[0059] The above description is only an embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as above by the embodiment, it is not used to limit the present invention. Any person with ordinary knowledge in the technical field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

[0060] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, technicians familiar with the field may make various corresponding changes and deformations based on the present invention, but these corresponding changes and deformations should all fall within the scope of protection of the claims of the present invention.

Claims

1. A lightweight remote plasma device, characterized in that: include: A housing comprising a gas inlet and a plasma outlet; wherein the plasma outlet is capable of communicating with an opening on a top surface of a semiconductor processing device; a plasma chamber disposed in the housing and connected to the gas inlet and the plasma outlet so that ionization gas can be injected into the plasma chamber from the gas inlet of the housing; as well as An electronically switched impedance matcher is disposed in the housing and coupled to the plasma chamber, and is electrically connected to an external radio frequency power supply to output radio frequency power from the radio frequency power supply to the plasma chamber; wherein the electronically switched impedance matcher comprises: A radio frequency input terminal, capable of being connected to an external radio frequency power supply; a first RF output terminal connected to the plasma chamber; an impedance detector electrically connected to the RF input terminal; An impedance matching circuit comprises at least one inductor and two sets of electronically switchable capacitor units, each of which comprises a plurality of switches and a plurality of fixed capacitors, wherein the fixed capacitors are respectively connected in series with the corresponding switches and then in parallel; as well as A controller is electrically connected to the impedance detector to detect the impedance value of the plasma chamber and output the detected impedance value to the controller. The controller controls a plurality of switches of each of the electronically switched capacitor units of the impedance matching circuit according to the impedance value.

2. The lightweight remote plasma device according to claim 1, characterized in that: The capacitance values ​​of the fixed capacitors are partially the same, partially different, or completely different.

3. The lightweight remote plasma device according to claim 2, characterized in that: The impedance matching circuit is an L-shaped matching circuit. The two ends of the inductor are respectively connected between the RF input end and the first RF output end. The two sets of electronic switchable capacitor units are respectively connected between the two ends of the inductor and the ground end.

4. The lightweight remote plasma device according to any one of claims 1 to 3, characterized in that: When the impedance value output by the impedance detector is substantially close to (50-J0)Ω, the controller stops controlling the switch of each of the electronically switched capacitor units of the impedance matching circuit.

5. The lightweight remote plasma device according to claim 4, characterized in that: When the reflected power is close to 0 or at least 0.1, the controller stops controlling the switch of each of the electronically switched capacitor units of the impedance matching circuit.

6. The lightweight remote plasma device according to claim 4, characterized in that: The RF power supply is a variable frequency RF power supply and is electrically connected to the controller; and After the controller determines that the currently detected impedance value reaches a preset impedance value, it outputs a hold signal to the RF power supply, so that the RF power supply adjusts its variable frequency, until the controller determines that the currently detected impedance value is substantially close to (50-J0)Ω and stops outputting the hold signal, and the RF power supply stops adjusting its variable frequency; The radio frequency power supply of the radio frequency power supply provides radio frequency power of 13.56 MHz ± 5%.

7. The lightweight remote plasma device according to any one of claims 1 to 3, characterized in that: The electronically switched impedance matcher further comprises: a second RF output terminal; and A radio frequency switch comprises a common end and two switch ends, wherein the common end is connected to the radio frequency input end, one of the two switch ends is connected to the impedance matching circuit through the impedance detector, and the other switch end is connected to the second radio frequency output end, and the radio frequency switch is electrically connected to the controller, and the controller controls its switching to selectively provide the radio frequency power provided by the radio frequency power supply to the plasma chamber or the second radio frequency output end.

8. The lightweight remote plasma device according to claim 4, characterized in that: The electronically switched impedance matcher further comprises: a second RF output terminal; and A radio frequency switch comprises a common end and two switch ends, wherein the common end is connected to the radio frequency input end, one of the two switch ends is connected to the impedance matching circuit through the impedance detector, and the other switch end is connected to the second radio frequency output end, and the radio frequency switch is electrically connected to the controller, and the controller controls its switching to selectively provide the radio frequency power provided by the radio frequency power supply to the plasma chamber or the second radio frequency output end.

9. The lightweight remote plasma device according to claim 5, characterized in that: The electronically switched impedance matcher further comprises: a second RF output terminal; and A radio frequency switch comprises a common end and two switch ends, wherein the common end is connected to the radio frequency input end, one of the two switch ends is connected to the impedance matching circuit through the impedance detector, and the other switch end is connected to the second radio frequency output end, and the radio frequency switch is electrically connected to the controller, and the controller controls its switching to selectively provide the radio frequency power provided by the radio frequency power supply to the plasma chamber or the second radio frequency output end.

10. The lightweight remote plasma device according to claim 6, characterized in that: The electronically switched impedance matcher further comprises: a second RF output terminal; and A radio frequency switch comprises a common end and two switch ends, wherein the common end is connected to the radio frequency input end, one of the two switch ends is connected to the impedance matching circuit through the impedance detector, and the other switch end is connected to the second radio frequency output end, and the radio frequency switch is electrically connected to the controller, and the controller controls its switching to selectively provide the radio frequency power provided by the radio frequency power supply to the plasma chamber or the second radio frequency output end.

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